Internal-combustion engine



L. 0. FagNcH. INTERNAL COMBUSTION ENGINE. APPLICATION FILED IULY I4., 1919.

1,381,294. mmm 14, 1921..

LOUIS O. FRENCH, OF MILWAUKEE, WISCONSIN'.

INTERNAL-connusrrou ENGINE.

Specication of Letters Patent. Patented June 14, 1921.

Application led July 14, 1919. Serial No. 310,841.

To all whom t may concern:

Be it known that I, Louis 0. FRENCH a citizen of the United States, residing at lVilwaukee, in the county of Milwaukee and State of lVisconsin, have invented new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

T 11e inventlon relates to an internal combustion engine in which air alone 1s compressed outslde the workinocylinder then .introduced into said cylinder at constant pressure and mixed with the fuel and the mixture burned. InA carrying out such a process on the one hand sudden and high expansion of the mixture must be avoided during the time the air is being introduced sc that the pressure in the cylinder will not exceed that of the entering air, and, on the other hand, the fuel must be in such a condition that ignition of the main charge will not be delayed after the air valve has closed. This I have accomplished by introducing the fuel into a chamber in communication with the working cylinder where it is partly or wholly` vaporized and mixed with some of the air being introduced and preventing the pressure of the contents of the cylinder rising above that of the air which is being introduced but bringing the 'contents of the chamber to a state to promote combustion throughout the mixture directly after the closing of the air valves A further object of the invention is to project the fuel into the main body of air in a nely divided state and this is accomplished by a partial explosion of the miX- ture While in the chamber which sbrays it through an oriice into the main bo y of air in the working cylinder, so the use of high pressure injection air or other gas is thereby avoided.

In the present constructions of internal combustion engine compression of the mixture or air alone is carried out in the motor cylinder. vIn the constant volume type this compression is comparatively low owing to danger of preignition. In the semi-Diesel i and Diesel engines the pressures are higher but in all these types of engines the temperature evolved during compression of the charge or the air in the cylinder is a limiting factor. Furthermore, where high pressures are employed as in the Diesel with compression/carried out in a single stage it is impractical to raise the compression pressure over that now employed because of the mechanical and thermal diiculties incident thereto.

One of the objects of this invention is to provide a construction in which the compression pressure is not limited by the temperature evolved durin compresslon and in which the work eXpen ed in compression is reduced. This is accomplished by compressing air and by that I mean pure air or air diluted with neutral gases by multistage compression with intercooling between the stages outside the worln'ng cylinder. Such a manner of carrying out the compression results in a saving of'work expended in compression with a resulting increase in thermodynamic efficiency 'and the temperature at which the air is delivered may be regulated.

Since the compression of air carried out in this manner with intercooling between the stages produces considerably lower temperavtures than singlestage compression to increase the mechanlcal and thermodynamic eiiiciency of this highly compressed air Y when used in the motor cylinder and also to provide for a temperature which though not execessive will be suiiicient to produce efficient combustion, the air is preheated before its introduction to the motor cylinder` and while this may be done by a separate source 'of heat it is preferable to use the waste heat generated in the working cylinder. The highly compressed preheated air is then'introduced into the working cylinder 90 vduring the working stroke and mixed with the fuel and combustion follows with expansion during the remainder of the stroke and exhaust takes place on the return stroke of the piston. By this procedure a gain in efficiency vWill result due to (l) multi-stage compression with intercooling, (2) preheat of the air, the lower initial temperatures that may be used, and (4) no limiting value to the compression dependent/fon teniperature.

A further object of the invention is to provide an engine of a iexibility approaching that of a steam engine in that both the amount of air andv fuel furnished to the engine may be readily controlled for different loads.

The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings: Figure 1 is a vertlcal sectional view of the engine embodying the invention; Fig. 2 is a detail plan view; Fig. 3 is a section taken on the -line 3-3 of Fig. 2; Fig. 4 is a detail section vievv o f the Working cylinder; Fig. 5 is a view s1m1- lar to Fig. 4, showing a modified form of certain details of construction; Fig. 6 is a view similar to Fig. 4, showing another form of certain detalls of construction.

The numeral 6 designates the Working cylinder, 7 .the Working piston, 8 the air inlet valve', 9 the exhaust valve `and 10 exhaust ports in the cylinder uncovered by the piston at the end of its stroke. -A connecting rod 11 connects the piston Withthe crank shaft 12.

-A gear 13 on the crankshaft meshes with a gear 14 on shaft 15 which through gears 16 and 17 rotates the valve shaft 18 carrying the exhaust valve cam 19 and theinlet.-

valve cam 20. A lever 21 carryin a roller 22 riding on the cam 19 .is move by said cam to open the exhaust valve. The air inlet valve is'given a variable lift dependent upon the load by means of a lever 23 having a governor controlled fulcrum 24 and connected by a link 25 to a lever 26 carrying a roller 27 riding on the .inlet cam 20. The fulcrum 24is mounted on a shaft 28 which has a crank 29 connected by a link 30 with the lever 31 of the governor 32. In this Way the quantity of air furnished to the Working cylinder may be varied to suitthe load.

The numeral 33 designates the low pressure cylinder of a multi-stage air compressor; 34 the high pressure cylinder; 35 and 36 the connected together lovs' and high 'pressure pistons Working in these respective cylinders; 37 the inlet valve -to the low pressure cylinder; and 38 the discharge valve thereof connected by a pipe 39 with an intercooler 40 from which the air is conducted to the high pressure cylinder through a pipe 41'. The head of the high pressure cylinder carries the .usual inlet and discharge valves 42 and 43, not shown in dei tail. The capacity 'of the low-stage compressor is preferably about equal to that of the Working cylinder though it may be made smaller if desired. As the demand for air is less at light loads, the amount of air entering the compressor may be controlled by a throttle valve 44 adjacent the inlet valve and provided with a lever 45 connected by a link 46 With a crank 47 on thel governor shaft, or by any other suitable unloading device controlled by the governor of the engine, or a separate governorv for the compressor. While I have shown the air compressor directly connected to the advance of that of the compressor so that4 the compressor is on its compressing stroke during the time the air valve 8 is open. While I have shown a two-stage compressor, it Will be understood that three or four stage compressors with intercooling may be used if desired and that the features hereinafter described may be used with a single stage compressor.

From the high pressure` cylinder the airl is conducted by a pipe 48 to a preheater of any suitable construction, such as a casing 49 and air headers 50 connected together by tubes 51. The exhaust gases from the ports 10 and from. a pipe 52 pass into a pipe53 and thence through the casing 49around the upper header and dthaata be` s' Sandthence through'fth'efut'ltfif The pipe 48 leads to the4 lower header 50 and a plpe 55 conducts vthe preheated air from the up er header to the air inlet valve 8. The cylinder head 56 containing the air inlet valve 8 may be water-cooledbut-I prefer to use it'as an additional means for preheating air and therefore provide it with an air jacket 57 communicating with the air inlet to the cylinder. In this way the air is first economicall compressed Vto the desired pressure an .is then preheated to increase its efiiciency.

The exhaust ports l0 may be omitted if desired and such products of combustion as are to be expelled maybe conducted through the port controlled by the valve 9 but by the use of the exhaust ports 10 a part of the exhaust products may be quickly expelled from the Working cylinder near the end of the Working stroke ,and passedv to the reheater in their then highly heated state. The exhaust valve 9 is preferably kept open until near the end of the return stroke of the piston though it may be closed before this so as to permit the piston to compress some of the exhaust gases into a chamber 58, 66 or 70 in communication with the Working cylinder, 'if desired.

Liquid fuel is fed through a pipe 59 to a spray valve 60 of usual construction and thence passes into the chamber 58, 66 or 70. The fuel is intermittently fed to the fuel valve by a suitable fuel pump (not shown) such as are comm'onl .used on Diesel or other oil `engines in which the amount of fuel supplied may be varied either by varying the stroke of the pump or by varying the time of opening of the suction valve of the' pump b mechanismA controlled by the govhead and has a throat portion 61 in communication with the working cylinder. This chamber is preferably ke t hot either by the heat of the products o combustion or by external heating so as to assist in vaporizing and igniting the fuel, though th1s may not be wholly necessary as other means hereinafter provided impart heat to the fuel in the chamber and'aid in ignition. The liquid fuel is introduced into this chamber durin or at the end ofthe upward stroke. ere the chamber 58 in open and free communication with the working cylinder at the' time the air is introduced the pressure in the cylinder might rise above that of the air enterinfr it and to avoid this difficulty I have provided a means for preventing the free passage of mixture from the chamber more articularly at the time the air is introduce As shown in Figs. 1 and 4.- this means Aconsists of a tubular projection or member 62 carried by the piston and moved thereby when in its upper position into the throat 6l of the chamber. There is a slight clearance between this tube and the walls of the throat to prevent the free passage to and from this chamber though permitting of some communication to allow some air to pass up into the chamber or a small uantity of mixture to pass down. This projection also has the function of varying the capacity of the chamber so that the percentage of air to fuel in the chamber gradually increases as the piston moves down during the working stroke so that when the air inlet valve has closed a mixture of air and such fuel as has become vaporized in the chamber is produced of such proportions as to form a combustible mixture which is ignited, either by the hot walls of the chamber, the heated projection or some ignition device, and passes down into the working cylinder where further burning takes place followed by expansion. The member 62 is preferably madesuch a length as to have its upper end still disposed in the lower end of the throat after the air valve closes, as shown in Fig. 4, so that the very small clearance between the tube and the throat forms an annular s ray orifice 63 through which the yaporize mixture and any fuel then remaining in an unvaporized state is sprayed into the iworking cylinder by the partial explosion in the chamber 58. In this way the fuel is efficiently introduced into the main body of the air 1n the working cylinder in a state of combustion immediately after the air valve closes. While a solid tube of the form shown in Figs. l and 4 of the drawings may be used, I refer to make the tube hollow so that a small) amount of air may pass through ports 64 into the interior 65 of the tube and then throu h small apertures 65', in the closed head of t e tube which will furnish a slightly greater amount of air to the upper part of the chami ber in a given time than would be afforded b the passage of air through the annular clearance space between the tube and the walls of the chamber.

In Fi 5 I have shown a slightly modified forml o construction in which a hot chamber 66 has a throat 67 of less diameter and a solid rod 68 having an enlarged head 69 is movable to a position within the tube during the commencement of the Working stroke so that the enlarged head is then above the throat and a farce passa e of air from the working c linder throng the annular space between -t e stem 69 of the rod and the throat to the upper end of the tube is afforded for a brief interval, but the area of this passage is constricted as soon as the head 69 moves down through the throat, said head forming with the throat, as before, an annular orifice through which the vaporized mixture or any fuel remaining in an unvaporized state is sprayed into the working cylinder by the partial combustion or explosion in the chamber 66 immediately after the air valve closes. The members 62, and 68 become highly heated during the operation of the engine and thus serve to heat thefuel within the chambers and serve as igniters. The members 62 or 68 need not necessarily be actuated by the piston and their form and the form and location of the chambers may be varied without departing from the spirit of my invention.

In Fig. 6 I show a chamber 70 communicating with the working cylinder through a port 71 and a tubular member 72 coperating with the chamber 70 in a manner similar to the constructions previously described. The piston 7 is here shown as cutting olf communication between the chamber and the Working cylinder during the first part of the working stroke. The member 72 is connected to a rod 73 which may be operated by any suitable mechanism to move the member 72 in a manner similar to the movement effected by the piston in the other constructions.

The o eration in brief is as follows: During t e upstroke or as the piston starts on its downstroke but preferably shortly before, during or shortly after the closing of the exhaust valve the fuel is introduced into the chambers 58, 66 or 70. Shortly before or as the piston starts on its downstroke the air valve opens admitting a charge of compressed air which may be preheated into the working cylinder for a part of the downstroke durln which time some air is mixed with fuel being vaporized in either of the aforesaid chambers but not to such an ex-A tent as to cause an explosion which would raise the pressure in lthe working cylinder above that of the entering air.

In the constructions above described di- A tion by the usual blow lamp.

rectly after the air valveclosesor nearly so the mixture then in the chamber flows in a burning state into the air within the cylinder and combustion of the whole arge followed byexpansion takes place during the remainder of the downstroke,

after which the products of combustion are expelled from the cylinder.

Starting of the engine may be effected in various ways. Where a portion of the fuel chamber is exposed, starting may be effected by preliminary'heating of the ex osed porhere the chamber is not ex osed prelimina heating ma be effected W ere a less volatile fuel is to be used by introducing into the cylinder a charge of a volatile fuel, such as gasolene and ignitinglthe mixture by the usual spark plug after t e air valve has closed.

In accordance with the provisions of the patent statutes I have described the principle of operation of my invention together with the construction which I now consider to represent the best embodiment thereof, but I desire to have it understood that the construction is only illustrative and that the invention can be carried out by other means within the scope of the claims.

What I claim as my invention is 1. In an internal combustion engine, the combination of a working cylinder, means for supplying compressed air toI said cylinder during a part of the working stroke, a chamber in communication with said cylinder, means for supplying fuel to said chamber, means for preventing the pressure of the contents of the cylinder rising above that of the entering air but permitting some air to pass into said chamber, and means for expelling the products of combustion from said cylinder.

2. In an internal combustion engine, the combination of a working cylinder, a piston, a chamber in communication with said cylinder, means forsupplying fuel to said chamber, means for supplying compressed air to said cylinder during a part of the working stroke, means for increasing the capacity of the chamber and admitting to it some ofthe air from the working cylinder, and means for expelling the products of combustion from said cylinder on the non-working vstroke of the piston.

3. In an internal combustion engine, the combination of a working c linder, a multistage air compressor providied with cooling means between the stages, means for pre- A heatin the air delivered by the compressor,

a cham er in communication with said cylinder, means for supplying fuel to said chamber,y means for supplying the 'preheated compressed air to said cylinder` during a part of the working stroke, means for preventing the pressure of the contents of the cylinder rising above that of the entering air but permitting some air to pass into sai chamber, and means for expelling the products-of combustion from said cylinder.

Y 4. In an internal combustion engine, the combination of a cylinder, a chamber communicating with the working space of the c linder, means forsupplying fuel to said c amber before the admission of air to the chamber, means for admitting compressed air to the cylinder during a part of the working stroke, means for admitting some of the air to said chamber but preventing a rise'of pressure in the c linder above that of the air entering the cylinder, and means for expelling the products of combustion from the cylinder.

5. In a two cycle internal combustion engine, the combination of a workiu; cylinder, a piston, an air compressor, ya va ve for adnntting a charge of compressed air into the cylinder during the working stroke, a chamber in communication with the working cylinder, meansr for supplying fuel to said chamber, means for permitting the passage of some air to said chamber but preventing ignition 0f the main body of fuel within the chamber until the air valve has closed, and means for expelling the products of combustion from the cylinder.

6. In an internal combustion engine, the

combination of a working cylinder, a piston,

a fuel receiving chamber having an opening into said cylinder, means for supplying fuel to said chamber, means for supplying compressed air to said cylinder during a part of the' working stroke, means for partially obstructing the opening of the chamber while t-he air is being introduced, and means for expelling the products of combustion from the cylinder.K

7. In an internal combustion engine, the combination of a worlng cylinder, a piston, means for supplying compressed air to said cylinder during the working stroke, a chamber having an opening into said cylinder, means for supplying fuel to said chamber, means defining with said opening an orifice through which the burning fuel `is sprayed after the admission of the air, and means for expelling the products of combustion from the cylinder.

8. In an internal combustion engine, the combination of a working cylinder, a piston, a vaporizing chamber in communication with said cylinder, means for expelling the products of combustion from the cylinder, an air valve, means for opening said valve to admit compressed air to the cylinder during the working stroke, means for supplying fuel to said chamber, and a movable member permitting some air to pass into the chamber and increasing the capacity of said chamber while the air valve is open.

- a vaporizing chamber in communication with vsaid cylinder, means controlling the passage ofthe products of combustion from the cylinder, an air valve, means for opening said valve to admit compressed air to the cylinder'during the working stroke, means" for supplying fuel to said chamber, and means moving in the chamber to increase its capacity and to permit some air to pass thereto while the air valve is open and cooperating with the chamber to form a spray nozzle.

.10. In an internal combustion engine, the combination of a working cylinder, a piston, a vaporizing chamber vin communication with said cylinder, means controlling the passage of products of `combustion from the cylinder, an air valve, means'for opening said valve to admit compressed air tothe cylinder during the working stroke, means for supplying fuel to said chamber, and a member movable into the open end of said chamber and out of the 'same for the purposes described.

11. In an internal combustion engine, the combination of a working cylinder, a pist0n, a vaporizing chamber in communication with said cylinder, means for supplying fuel to said chamber, means for supplying compressed air to said cylinder during the working stroke, means for increasing the proportion of air to fuel in said chamber as the air is being introduced into the cylinder, and means for expelling he products of combustion from the cylin- 12. In an internal combustion engine, the combination o-f a working cylinder pro` vided with exhaust ports, a piston controlling the passage of exhaust through said ports, an exhaust valve, a multi-stage air compressor provided with cooling -means between the stages, a preheaterfor the air delivered by the compressor, means for conducting the exhaust from said ports and valve through said preheater, an air valve for admitting the preheated compressed air to the cylinder during the working stroke, a chamber in communication with said cylinder, means for supplying' fuel to said chamber, and means for igniting the main charge on the closing of the air valve.

13. In an internal combustion engine, the

combination of" a working cylinder, a -pis-l ton, a multi-stage air compressor provided with cooling means between the stages, means for preheating the air delivered by the compressor, a chamber in communication with said cylinder, means for supplying fuel to said chamber, anair valve for admitting the preheated compressed air to the cylinder, means for admitting some of the air from the cylinder to said chamber but )reventing a rise of pressure above that of t e air entering the cylinder, and means Afor expelling the products of combustion fronr the cylinder on the non-working stroke.

lfl. In an inter-nal combustion engine, the combination of a working cylinder, a piston, a multi-stage air compressor provided with cooling means between the stages, means for preheating the air delivered by the compressor, a vaporizing chamber in communication with said cylinder, means for supplying fuel to said chamber, an air .valve forV admitting the preheated compressed air to the cylinder during the worklng stroke, means permitting the passage of some air to said chamber and increasing the proportion of air to fuel therein while the air valve is open, and means for expellin the exhaust gases from the cylinder. 15. n an internal combustion engine, the combination of a working cylinder, a piston, a vaporizing chamber in communication with said cylinder, means for expelling the products of combustion from the cylinder, means for supplying compressed air to said cylinder during a part of the workchamber, and a member carried by the piston and movable into and out of said chamber to admit some air thereto and control the ignition of the mixture therein.

16. In an internal combustion engine, the combination of a combustion chamber, means for supplying compressed air to said chamber, a vaporizing chamber in constant communication with said combustion chamber, means for supplying fuel to said vaporizing chamber, means cooperating with said vaporizing chamber to form a combustible mixture therein and preventing a rise in pressure in the cylinder over that of the entering air.

17. In an internal combustion engine, the combination of a combustion chamber, mea-ns for supplying compressed air to said combustion chamber, a vaporizing chamber in communication with said combustion chamber, means for supplying fuel to said vaporizing chamber, a piston, and a member carried by the piston and movable into and out of said vaporizing chamber to control the passage of air thereto.

18. In an internal combustion engine, the combination of a working cylinder, a piston, a multi-stage air compressor provided with cooling means between the stages, means for preheating the air delivered by the com- .ing stroke, means for supplying fuel to said i pressor, a vaporizing chamber in communia member carried by the' piston and movpurv with exhaust ports, a piston contro ling the passage of exhaust through said ports, an exhaust valve, an air compressor, a prehealtcr for the air delivered by the compressor, means for conducting the exhaust from said ports and Valve through said preheater, an air valve for admitting the reheated compressed air to the cylinder uring the Working stroke,/a chamber in communication With said cylinder', and means for supplying fuel to said chamber.

20. In a two-cycle internal combustion engine, the combination of a Working cylinder, a piston, a multi-stage air compressor provided with cooling means between the stages, means for preheating the air delivered by the compressor, a chamber in communication with said cylinder, means for supplying the preheated compressed air to said cylinder during a pant of the out-stroke of the piston, means for supplying fuel to said chamber, means for expelling the products of combustion from the cylinder during the in-stroke of the piston, and means 21. In an internal combustion engine, i

the combination of a Working cylinder, means for supplying compressed air to said cylinder during a part of the Working stroke, a chamber in communi-cation with said cylinder, means for supplying fuel to said chamber, means to spray the contents of said chamber into the air in the cylinder on the expansion of said contents during the Working stroke, and meansfor expelling the products of combustion from said cylinder.

22. In an internal combustion engine, the combination of a Working cylinder, means for supplying preheated compressed air to said cylinder during a part of the Working stroke, a chamber in communication With said cylinder, means for supplying Yfuel to said chamber, means to spray the contents of said chamber into the air in the cylinder on the expansion of said contents during the Workingr stroke, and means for expelling the products of combustion from said cylinder. v

In testimony whereof I affix my signature.

LOUIS O. FRENCH. 

